1. Field of the Invention
This invention relates to data verification and more particularly relates to read back verification of stored data.
2. Description of the Related Art
A data processing system may often copy significant quantities of data to storage devices. The data processing system may store the data to an archival copy of the data. In a prophetic example, the data processing system may store archival versions of digitized print, photographic, film, and/or audio media. Alternatively, the data processing system may store the data as a backup copy.
A user of the data processing system may require verification that the copied data is a faithful copy of the original data. To verify that the copied data is a faithful copy, a storage device may read the copied data as it is written to the storage device using a read-while-write process. The read-while-write process confirms that the data is written to the storage device just as the data is received by the storage device. Unfortunately, the read-while-write process does not check for errors transmitting the data to the storage device. In addition, the written data may be corrupted by subsequent writes.
As a result, the user may require that the data processing system read the copied data back from the storage device and compare the copied data to the original data to verify that the copied data represents a faithful copy. Such a read back verification process assures that the data is copied completely and accurately. Unfortunately, reading back and comparing the copied data with the original data requires significant communications and processing bandwidth, particularly when significant quantities of data are copied to the storage device. Requiring that the data processing system to read back and compare all of the copied data can significantly increase the cost of storage and communication devices for the data processing system.
From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method that perform reduced bandwidth read back verification. Beneficially, such an apparatus, system, and method would verify that data is completely and accurately copied while reducing bandwidth demands on the data processing system.